Just so you know AT&T and Comcast use the same Network Core (Infrastructure)
IN A GOOD AMOUNT AREAS!!! BUT NOT ALL!!!
Most incidents that happen with Comast, regarding internet speeds and quality, happen with AT&T as well and I have proven with a friend who owns uses AT&T, and I use Comcast obviously o.0... we both witness the issues at the exact same time.. although not all the time of course. The main issue as I investigate is that NA's ISPs are realitvily cheap when it comes to expansion instead of doughing out the money to upgrade to more realiable transmission line (fiber). They rather instead keep bonding copper wires that have been already laided out by previous companies or they lay more for cheaper opperating costs. Sad part is Comcast charges us fiber prices for our top speed which isnt nearly the speed of fiber (300 down/ 200 up). Google Fiber is the right idea. Hopefully comast gets the same idea soon or I will be moving to get Google's service.